Garden tractor



June 20, 1950 o. w. SHELOR 2,512,443

GARDEN TRACTOR Filed March 7, 1946 I 3 Sheets-Sheet 2 gmwwbo b OLIE W. SHELOR June 20, 1950 o. w. SHELOR 2,512,443

GARDEN TRACTOR Filed March 7, 1946 3 Sheets-Sheet 3 Patented June 20, 1950 GARDEN TRACTOR Olie W. Shelor, Salem, Va., assignor of forty-nine per cent to Furman Whitescarver Application March 7, 1946, Serial No. 652,687

4 Claims. (01. 97-48) This invention relates to tread type garden tractors. I

One of the objects of the invention is to provide'a garden tractor having a narrow tread so that the tractor can be steered by tilting it sidewise, the traction flight of the tread being longitudinally convex in a downward direction with the point of greatest depth substantially beneath the center of gravity so that the tractor can be rocked forwardly with comparatively little effort to enable it to be steered by the forward portion of. the tread when the tractor is tilted in either direction.

Another object of the invention is to provide a tractor of the type described, having tread cleats positioned to compact the soil with which they intergear, laterally so as to hold the tractor from sidewise slipping, particularly when working across a slope.

'A further object of the invention is to provide a tractor. which travels upon continuous rails constituted by the straight sides of the tread chain links, thereby preventing vibration or bumpiness in the forwarded movement of the tractor.

Still another object of the invention is to provide a. tractor resting upon the tread by means of idler gears, the teeth of which do not roll upon the chain links but merely loosely project into the link openings to guide and hold the tread in place, the driving gear the teeth of which, of course, roll upon the transverse elements of the chain links, being positioned above the traction plane, protected by virtue of its elevated position from becoming clogged by mud and clods.

Another object of the invention is to provide in agarden tractor of the type described, an implement beam pivoted close to ground level to prevent undue tendency of the implement to lift out of the ground.

A further object of the invention is to provide a spring released clutch of the belt tightener type between the engine and drive shaft, normally engaged, but tripped by a trigger to release it, this arrangement being particularly useful in connection with a governor controlled engine that speeds up upon increase in load, to prevent stalling of the engine when the tractor encounters insurmountable obstacles such as large roots.

A stillfurther object of the invention the provision of a unitary mount for the power-plant, including the main drive shaft, separable from the tractor frame and adjustably slidable relative thereto-to regulate the tautness of the driving connection between the main drive shaft and the tread driving gear.

Other objects of the invention will appear as the following description of a preferred and practical embodiment thereof proceeds.

'In the drawings: v

Figure 1 is a side elevation of a, tractor embodying the priciples of the invention. I

Figure 2 is a similar view from the reverse side: Figure 3 is a top plan view; Figure 4 is a front end elevation;

Figur 5 is a fragmentary bottom plan view of Figure 9 is a, fragmentary view in vertical sec tion of the means for adjusting the motor base plate relative to the platform which supports it,

v as seen in Figures 1 and 3.

Referring now in detail to the drawings, the numeral 1 represents in general the tractor frame which, as can be seen in Figure '4, is preferably an integral heavy sheet metal member bent in deep channel form to provide side plates ,2 and 3 joined at the top by a flat portion 4, constituting a support for the removable power plant, as will appear. The forward part of the frame has the upwardly projecting integral side extensions 5 and 6 joined at the top by a plate I, the latter forming a support for the implement lifting mechanism.

The tractor handle bars 8 are adjustably connected at their forward ends to the upright members 9, secured to the tractor frame, the adjustment consisting of a'series of several holes I!) in thehandle bars,'any one of which may be engaged by a bolt l l, passing through the upright,

-9. Intermediately thehandle'bars 8 are each supported by a strut I2, having an intermediate pivotal joint [3 and having its lower portion l6 v rigidly secured, as by welding, to the extensions 5 of the tractor frame; The struts l2 cooperate with the adjustment at the forward ends of the handle bars to raise or lower the handles. on

top of the plate I in a middleposition, as shown in Figure 3, a bracket I! is welded or otherwise secured forming the pivotal connection for a bell crank lever I8, the lower arm I9 of which is connected by the link 20 to the middle portion of the implement bar 2| to lift the latter when the lever I8 is pushed forwardly. The topof the bracket [l is formed as a toothed sector 22 engaged by a pawl 23 carried by the lever 18 and actuated through the lever 24 and connecting rod 25 to hold the lever I8 in fixed position.

The implement bar 2| is carried at the rear ends of curved arms 25 which are deeply convex in an upward direction and pivotally mounted at their opposite ends to the opposite sides 2 and 3 of the tractor frame at the points, ZLclose to ground level so as to inhibit the undue tendency of the implements to rise out of the ground.

- The implement beam 2| is preferably a hollow rectangular tube having aligned openings 28-, through its upper and lower walls at spaced intervals, three of such openings being shownin the drawings to receive the shanksZS oi cultivating implements such as thehoes 30: The openings are preferably but not necessarily polygonal in shape, to prevent rotation of the stems 23, the. latter being secured by the set screws 3|. The implement beam 2| is further provided with similar aligned openings 32 in. its front and. back walls, in alternate arrangement with the openings 28 to receive the shanks 33 of the hoes 3d. The shanks 33 are longer than the shanks 29. and more deeply curved so as. to bring the hoes 34 to the rear of 'the'hoes 30,

The tractor is driven. upon an endless tread which in general is designated by the reference character 35, and. comprisesa chain. having links, the side members 36, of which are straight in a vertical plane, as shown in. Figure 6. The side members 35 are pivotally connected. at the ends of the transverse rollers 3Tin conventional manner. oppositely inclined cleats 38 and 39 are fastened to the outer edges. of the side members 36' by welding or casting of alternate. links, The oppositely inclined relation of adjacent links 38 and 39 forms alternate. wide and narrow spaces between the cleats on each side of the tread. To prevent the weight ofthe tractor from causing the tread to sag, in the span between the wider spaces, a short cleat' l0, uniiorm in height with theother, cleats is welded to the sidemembers of the intervening link, so as to project only into the wider spaces, This cleat is arranged perpendicular to the directionof travelof the tread, and in eifect forms the bisector of'the angle between adjacent inclined. cleats;

Itis obvious that any tendency of the tread tn. sliplaterally relative tothe ground with which the cleats are inter-engaged will cause a wedging actionof the soil which lies between adjacent in.- clined cleats which willcompact the soil and resist such tendency to slippage. This keeps the, tractor from sliding laterally when working across. a;.sl'ope..

Tne tractor rests uponthe tread, by means-cf, the three idler gears 41 42-. and '53, journaledmpon rods 44,,the ends of which pass through apertures. in the side plates 2. andS'and are secured by nuts. To provide adjystmentfortheseidler gears, there are several apertures 45in vertical and horizontal series, into any one of whichthe rods maybe. secured. It will be noted that the middle idler gear 42; normally projects downwardly. to; a eater depth than the endidlers 41 andjf thus giving a longitudinal crown or rocker-.9; to the lower or traction flight of the tread. Thevmiddle idler gear 42 is substantially beneath thecenten of, gravity of the tractor so that the weight oi the. tractor is substantially evenly balancedonoppo: site sides of the axis of this gear. Thegrgund engaging portion, of, thetread. may beregarded as being differentiated into two flat traction flights, one between the front and intermediate idler gears Al and 42 and the other between the intermediate and rear idlers, assuming the tractor to be in a position of substantially unstable balance with the points of the shovels touching ground; only the middle part of the tread, beneath the middle idler 42, will be pressing the ground. The operator first presses down the handles slightly to cause the shovels to,v penetrate. Then the shovels will begin to resist the forward movement oft-he tractor, and since the pivotal connections or the implement beams Zfi is above and to the rear'ofthe axis of the intermediate idler 42, the resistance Off the. shovels will tilt the tractor dovrrrt wandthe rear until the rear traction flight or the treadis pressing on the soil throughout its whole area. Beyond-this position, the tractor will not tilt; so that the shovels remain at a fixed depth within the soil.

When the soil is very-soft and loose, the shovels may tend to pullout of the ground, but under this condition, of. soil. the, weight of the tractor sinks the rear. traction flight of thetread to a. slight depth beneath, the surface so that. a portion of the. upwardly inclined forward, flight i engaging h s i n. a upward nc in d. p a w h keeps the tractor tilted rearwardly and holdstheho eljs ati hei'r depth.. .unte ns he de to pull out of the soil.

When, the tract'on riding solely upon the rear traction f ght of the tread is tilted laterally to right or left, it will steer to one side because the ea s t at s .dis s p annn e pposite de ne o r a st t actio bei g f set a ra ly'f om t e.mi dle o s udinal e t a e; through" the tractor; H oweventhe'radius of the steering arc' is greatly shortened by tilting the tractor forwardly byslight' upward pressure upon the handles to bringmore or less of theupwardly inclined forward traction flight 1 against the ground; and then tilting the tractor laterally. This throws the forward flight to the right or left, asthecase maybe, resulting in quick deflec fi tion ofthe tractor; By this means it is possible" to cultivate a row of corn by steering the tractor in a sinuous path aroundalternat'esides of'successive stalks alongthe'row; then turning the tractor around and' steering itin a similarpath 9;- aroundthe other alternate sides of the stalks.

" Itwilhbeobvious from-Figure G-tha-twherethe drive chain passes around thedrive gear 41, ad'- jacent linksare" angularlydisposed so that a straight line joining the-outer pivots oitwo ad 5 5 ..jacent links will-be-achord of the'pitch linedetermined by the-axes of the link-s and less than the sum-of-Lthe lengths of said adj a-cent'links; but that-where thechain travels in a straight flight, a straight line between the outer pivotsof the ad'- on j acent links will-be equal to the sum of the-lengthsof said links. Consequently, if theidler gears; 42 and. 43i-whiclr operate upon strai'ghh flights of thechain were identical with the drive gear; 41 theteethor-the idlergears would not be synchro- 6e nizeds withthe openings: in-the links, since there would: be. an -accumulative-gain -in--the-.:presenta-- tion1.of. the. links; maths-straight flights tothe teeth .of; the. idler. gears; Thisswould cause the-- teethof: the idlersi-tocrides up upon-the rollers of the links until .the freely turning-eidlers slip b'ackin place, givingaobjectionable vertical. vibration or bumpiness inthe operationioftheltractors There f r the-idler gears have; a tooth spacing which-- meshes the link; openings-.inlthe; straightilights :of'

h c r that. is; the; tooth. spacing" is; slightly-=- the teth will not tend to; ride the rollers, notwithstanding variations in the angularityof adjacent straight traction flights, incident to adjustmentigf the frocker on the lower traction. portion of the tread. The idler gears function solely toguide and hold the tread in place upon thegears, The gears are provided laterally on opposite sides of theteeth with circular peripheral flanges 4.6 which rest upon the side'members 35- of the. chain. Since these :side. members are strai ht, they form a continuous straight track upon which the peripheral flanges 46 smoothly roll, thus avoiding vibration or bumpiness which characterizes thosetractors inwhich the gear teeth ride upon thechain.

The tread 35 passes about a drive gear 47, which is carried by-apost 48, mounted in bearings 49, securedto theopposite side frame plates 2 and 3 attheir rearward ends. This gear is positioned atya considerable distance above ground level where it, is protected from being clogged with' mud. anddebris lifted by the tread. Substantiallyall of such obstructive matter falls from the tread in that; part of. its travel. from the idler gear 4| to the drive gear 41. The teeth 50 of the drive. gear fit the chain links and ride upon the rollers 31. This gear does not have lateral flanges which contact the side link members 35.

The power plant comprises a base plate 5!, which rests upon the platform 4. It has longitudinal slots 52', through which bolts 53 pass, said bolts screwing into'holes in the platform 4. At its rear end the base plate 5| has an upturned flange 54, provided with holes 55. The extensions 5 and 6.0f the tractor frame have lugs 56.

stamped out perpendicularly thereto, said lugs beflange 54, by means of which the longitudinal adjustrnent of the power plant upon the platform 4 islfdetermined. When in adjusted-position the bolts, 53 are screwed tight, fixing the position of the power plant. The power plant comprises an internal combustion'motor 60, mounted upon the base plate 5| and a main drive shaft 6| journaled inbearings 62, also fixed to the base plate. The drive shaft 6! carries a large pulley 63, which is belt driven from the shaft of the motor, providing considerable gear reduction. The drive shaft 6| also carries a sprocket 64 on which is mounted a chain 65 which connects the driving shaft with a sprocket 66 on the shaft 48 of the drive gear 41. The tautness of the chain 45 is regulated by adjusting the longitudinal position of the power plant in the manner above described.

The motor is not part of the present invention, and therefore need not be specifically described. It is preferably of that commonly known type which is controlled by a governor so as to increase the speed of the motor when the load increases. Thus, when the tractor encounters anobstruction in the ground, the motor speed automatically increases to give more power to overcome the obstruction. Ordinarily, in known garden tractors, if the obstruction is insurmountable, it inevitably causes the motor to stall. This isga great'nuisance, foritiinvolves frequently restarting the motor. In the present invention, stalling of the motor is avoided by the followingcontrol. The belt 61,:whichdrives the pulley 63 from the motor shaft, is loose enough to slip. It is brought into operative engagement with the pulley 63 by means. of a belt tighte ening pulley 68,.mountedon a pin .69, carriedby one end of a;.bell crank 10,-pivotally mounted on the motor base The other arm of th bell crank 1.0, is connected by means of a "rod .11 tos a lockin lever 12, pivotally mounted on a plate" 73 secured to one of the handle bars 8 adjacent the handle. :The lever 12 has-alcurved end 14,150.

which the rod llisnpivotally, connected; When the lever F2 is pushed forwardly againsta stop; 75 on the plate 13, the pivotalsconnection:bee; tween the rod ll andleverJZfis moved beyond;

the dead center represented by the-pivotal con nection 16 of the lever 12 withithexblockalii.

This movement rocks the bell .cra'nkllllcso 'as to bring the pulley 68 into tightening engage-'21 ment with the belt BL and locks it in thattposition. Thisis the normal positionzof the parts.

in the operation of the tractor. The belt tightening pulley :is released by means of;. atri ggerii consisting of a curved lever 11, pivotally'mounted:

upon the plate 1.3, having one end .lflpositioned to engage the curved end of .the .lever lz and throw it intov release position. with-=respectto the dead centerl'ii when the triggeris p'ulled.- When:-:.

the tractor meets an. obstructionythe. motor speeds. u and the additional powenvthereby provided automaticallyovercomes the obstruc-i tion. However, if vthe motor beingsxato :labor, the operator quickly pulls the trigger, releasing the pulley 68, 'which is retracted by means of. the

spring l9, which is anchored at one end to lthe tractorframeand connected at the other end: to the bell crank 10. This releases thevm'otor fromall load and it recovers withoutsstallin'g.

The tractor is then manually tilted or pulled" back so :as to avoid the obstruction (and: driving the tlever 112a operation resumed by again pushing forward. 1 At its front end the tractor is.

side plates 2 and 3 of-the tractor frame. in its lowered position, the stand encounters stops Bl on the tractor frame, and'becomesa.

stable support. for the tractor.. When in elevated position, it constitutes a handle by means of which. the forwardendof the t'ractor'may;

be lifted.

Figure 8 shows a slightmodification ofthe in...

vention in which two parallel treads 82 and 83 may be employed, ealch identical with the single tread 35, but which may be narrower and slightly spaced. These give a somewhat wider base of support and ease the burden of holding the tractor upright for straightaway travel, and make possible a multiplication in the number of (cleats, which may to some extent improve the traction.

The unbroken earth ridge between the treads may be of advantage in holding the tractor to a straight course, particularly when crossing a slope. The cleats themselves have a cultivating function in breaking the surface crust, and a finer rcomminution of the crust is possible where a double treat is employed, than in the case of a single tread. Duplication of the idler and driving gears is of course required for the use of the double tread.

spran While I 'liave irr. the above descriptionidisolosed what: I believe: to' be a preferred and practical embodiment or? the invention;- it: will be under stood by:those skilled the art thatthe specific details officonsiniuctionsand arrangement of parts are; by way." of illustrationi and not; to be .cen-'-- struedi as limiting the scope of: the: invention.

WhatI' claim: as myi-inve'ntionzisz 1. garden: tractor comprising: a.- frameincludingisidemembers and having operating harrdles .atthe rear thereof; spaced front. and rear idler. gears and an intermediate idler gear all supported by: said side members-and journaled therebetween, .a drive gear, an' endless tread com-- prising a chain. with: traction: cleats: passing about said" gears in mesh:- therewith. and off such width as to? be within: the confines: of said. side members, said intermediate: idler gearextend ingrdepthwise? below said? :front. andi rearidler ears'zgiwng a; longitudinal rocker action tot-he traction. flightaof said tread; theashape' of said:

tread! defining forward and rearwardi straightv traction: portions: upwardly inclined from an apex; an implement beam" extending-rearwardly' of? said frame having: its forward end pivotedthereto: at aipoint between the. axes of said: in'- termediate; and" rear idler. gears; and above a plane embracing said' axes whereby the drag of roundlpenetrating' implements carried by said implementt-beampauses.saidtractor to ride upon said rearward.tractionjportion;said tractor being. tiltable forwardly about said apex by upward pressureonsaid handles to bring at least part? of saidaforward"traction portioninto ground engagement; torenabla steering. by tilting said tractor laterally;

2..A-. garden tractor as1claimed. in claim I, inwhich: the; intermediate idler gear is' adjustable in a vertical direction to: vary. the angle thaapex:

3;. A gardentractor comprising a. frame hav ing. side memhers,- spaced: rrontand' rear idler gears-supported by said side :members and: joinnaledstherebetween; a drive gear mounted :onsaid frame above said idler gears, an endless: tread comprising a chain-1 with traction: cleatsx passing aboutz'said front and? rear: idler. gears and said drive, gear ine mesh therewithaand" having suchwidth as tobe-.within\the:confines= of said sidemembers; an intermediate idlen gear also sup ported byv said; side: members: and journaled therebetween projecting vertically downward furthers than said front. and? rear idler: gears and; in mesh with said tread lchain giving a longitudinal rocker action to the traction: flight oisaidi tread, said chainhaving: straight sided 3;. linkstrie ides of-wlii'cll forma' 't'r'aclf, saididlerlgears having circmar: flangesthatride uponn-s'aldi tracli whereby said cnaim rides withits pitch line offset with respect tothe pi-tehline of said idler gears.- I

A garden: tractor comprising a. frame and" side members; spaced front and" rear idler gears supported by said side" membersand journaleds therebetween -adrive ear mounted on-said frame above; said idler gears,- an endless tread com:

prising a lcliaiir with traction cleats passing about said frontand: rear idler gears and sal'ii drive geanin mesh therewith and having suclr Width; as to: bewithin the" confines 01 said side members, an intermediate idler gear also sup? ported; by said side nienilie'rs' and joumaled thereloetween' projecting vertically downward further than said front and'rear idler gears mesl'l with. saidtread-i chain: giving a longitudine-15 rocker action hr the traetion ilightiofi said tread, said ehain having straight; sided the-.sides of whiohifomn a track, said idlerge'eara having circulariflangesthat rid-e upon: said traek said: chain turning about said drive gear": on a. pitch line determined bytheaxes of" said links, the teeth of said'i'dler g earsbeing spaced" aparik av reater distance than the teeth of said' drive: gear to: secure accurate mes-ii with the straight. portions: of the; traction fii'ght of said chain.

REFERENCES CITED/ The following, references are. ofireoordin the; file. of. this .patent:

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